Cadillac Flathead Tech Contributions

[fiftyv8]

I wish to start a Cadillac Flathead Tech Thread where folks can contribute some interesting or technical facts to help out any forum viewers who care to take this information for their own project needs and as it is a Cadillac Modified Forum lets get some of the old school stuff included.

Anything can go as long as it is engine tech tricks, specs, leads to suppliers, engine modifications and how to's.

I would hope that guys out there would register their interesting project or car build.

Lets see if we can get some system to this like, say about your project, start your thread "My Project" or "Tech Hint"

"My Engine Details"  etc.

Thanks guys  lets ee what we can come up with.
I will start!

[fiftyv8]

"My Project" 
Hot rod model T 3 window pickup sitting on a 1932 modified Ford chassis running a 1950 Cadillac rear end and same year spindles on a front  Ford dropped axle.
I am trying to incorporate power steering and a/c to my engine just to see if it can be done.


"My Engine Details"
I have a 1938 ex-military 346 block which I have sleeved back to 322 with .010 over bores and same the.010 under in the crank, I have hardened valve inserts fitted and my cam has a mild regrind.
I have a Burrel 2x2 inlet manifold and plan to run a twin exhaust sytem thru home made extractors/headers.
I would like alloy heads but have settled for the originals for now.
I plan to run all modern Vee belts and pulleys.


"Tech Hint"
CAM
Beware with cam regrinds since you can run yourself out of hydraulic lifter travel thru regrinding the cam and lack of knowledge when installing new valve seats.
The trick to solve this if you have problems is to have the ends of all the valves staliite welded about an extra 1/8" at the ends and then have each valve stem reground and fitted individually to the required tolerance.
From memory it is between .030 to .075 clearance range.

REMOTE OIL FILTER
Is hooked into the main oil gallery at the front drivers side of the block and the return supply may need to be installed if not already there by using a special hollow bolt fitted into one of the existing timing chain cover bolt holes or a hole could be drilled into a suitable place in the timing cover and the oil directed onto the timing chain or away from the front seal.

CRANK PULLEY
A cheap and easy way to get a modern Vee style bottom pulley is to use an aluminum after market small block chev item with your choice of 1, 2 or 3 grooves as required. You machine off the rear lip and redrill the new bolt pattern using the stock Cadillac retainer ring washer from the old pulley as a template.
Nn need to even weld up the old holes as they mostly disappear behind that retainer washer and if you dont want the holes and can not weld aluminum just cut up a couple of pieces of round aluminum rod the maching size and gently press them into the old chevy holes. Presto a polished Vee groove crank pulley for about $30+ from ebay.

More secrets when I have seen some others.

[CarFreak]

I've only owned stock flatheads so that's what comments I'll offer. 
Stole this from the Motherboard but useful if you have a 6v w/hard hot re-start problem.

Starter Grounding Stud

The current path to the actual ground on the starter goes through several mating surfaces which may not make good enough contact, so because of the couple hundred amperes flowing through the starter motor, you can lose a volt or two. On a warmed-up engine, the starter cant develop enough torque to crank the engine. I found the key to all this in my 41 Oldsmobile. They have a grounding boss on the commutator end plate of the starter, and thats the place where the starter is actually grounded. Oldsmobile starters always ran fast, and that is the reason. Its a 41 98, and has essentially the same starter as on the Cadillac V8.

 I checked out a couple of Cadillac end plates (the one on the opposite end from the flywheel housing) and a hex head cap screw can be mounted in one of the little wells inside the end plate, and protrude  to the outside.  If the grounding battery cable is connected to this grounding stud, there is no resistive path through the starter to ground; its right at where the brushes connect to ground. I used a 3/8-16  or 24 thread, with a lock nut on the outside of the starter. Grounding to the engine and chassis will simply flow through the starter to the engine in the opposite direction. No further ground straps will be necessary.

The heart of this is: when new, all parts of the starter were clean and bright. All connecting points were also clean and bright, so there wasnt a grounding problem. But as years age the parts, the contact between parts of the starter and to the flywheel housing degrade, and you lose voltage. Youd be shocked at the performance of those starters. They crank like they have 12 Volt on them. 

[Rhino]

This is absolutely correct, I added the ground bolt to mine. Then I got new brushes installed as well. Make sure they use the right ones!

[Restomod 40]

What a great idea!  I will watch this thread carefully, and maybe contribute something useful along the way.  I would love to see some old school speed tricks for the 346.

[CarFreak]

Another stolen quote from the Motherboard - but better to share & preserve this info then to let it disappear.

Shifting stock Hydramatic into Reverse:

On all Hydra-Matics, from 1940 (Oldsmobile) throigh 1950, the transmission has to engage before an attempt to shift into reverse position.

On the prewar transmissions, there was no safety device to prevent going into reverse and damaging the reverse pawl and the reverse planetary drum. In the 1946 and later, there is a reverse blocker piston in the valve body which blocks the selector from going into the reverse position before the transmission engages.

In all of those models, from 1940-1950, THE REAR WHEELS MUST BE TOTALLY OUT OF MOTION as you drop the lever into reverse.

In 1951, a cone clutch device was added to the reverse selector and its possible to safely yank the lever into reverse as soon as the engine fires, without problems. I have a 51 transmission on one of my 41 cars, and its nice to be able to get reverse without a wait.

Now, if youre not sure of what transmission you have, check the following. Look at the transmission from under the hood on the driver side. If there is a large hex plug at about 1:00 on the front of the transmission case as you're looking at it, its postwar. That (regulator plug) wasn't on the prewar boxes.

Also, if the selector lever detent positions are relatively soft, its prewar. On the postwar models, the selector detent was on the control valve body in the transmission, and the positions are very sharp and pronounced.

[Geoff]

Speaking of flathead Caddy's, here's some interesting flathead parts on eBay.  Item  #150223520154.
 

[STDog]

Speaking of flathead Caddy's, here's some interesting flathead parts on eBay.  Item  #150223520154.

Item  #150223520154
1937 to 1948 Cadillac flathead solid lifters hot rod

Solid lifters for a flathead 

[fiftyv8]

Can anybody tell us if they are the real thing as to me they look home grown and would probably not last long with wear!

[Big Fins]

There is even a set of solids on the M/B for sale. But they could be the same ones!!   

Fins

[fiftyv8]

Come on guys dont let this thread die in the arse, get some helpful hints going.Somebody must have done an distributor modification or extrators etc.

This site is not living upto my  MODIFIED CADILLAC expectations and probably not yours either if you have flathead engine, but you need to contribute to make it work.

[/u]

I am currently doing an install of a new seal into the timing chain cover.
Once installed and working I will post the details, seal costs about $6.50 and you end
up with new technology sealing system without paying cadillac drug prices for parts.

Wait until I can get some decent gaskets made at about half the prices being asked right now.

Maybe I am out of order here, but is anybody actually out there with another cadillac flathead
that has or is doing some sort of modifications??

[EZ]

Sorry Dude.  Mine's a '66 Coupe DeVille.  No flat head here.  Since this is the "modified"
chapter I would think that most of us in here would swap the stock flat head motor for
a 472/500 or something similar.  Maybe.........maybe not.   

Have you tried posting your idea on the CLC board?  More "restoration type folks" over there I bet.
I sure wish you had a 60's Caddy.  I bet you could really help me out..........   You seem like you
know your stuff!

Good luck!   

[STDog]

I sure wish you had a 60's Caddy.  I bet you could really help me out..........   You seem like you
know your stuff!

Like EZ I could be more help with later models, BUT I'm glad you have a flat-head.

I wish I had one.

Post any info you have. Maybe we can get more flat-head owners ere.

I'd love to see some V12 and V16 info too. Early V16, not the l-head 16.

[C.I.D Vicious]

FiftyV8

 I don't think folks are holding back. My guess would be your just blazing a new trail. Doubt we have many flathead modifiers here yet. That just makes what you have to say, that much more valuable to the club.

IMHO if you share what you know here, that is what will attract more modified flathead enthusisats to this board. It may take awhile untill you find others to exchange ideas with. My guess is "if you post it, they will come."

 While I don't own a flathead Cad, I sure enjoyed the info you posted. 

[The Tassie Devil (Bruce Reynolds)]

Come on guys dont let this thread die .... get some helpful hints going.Somebody must have done an distributor modification or extrators etc.

This site is not living upto my  MODIFIED CADILLAC expectations and probably not yours either if you have flathead engine, but you need to contribute to make it work.

[/u]
I am currently doing an install of a new seal into the timing chain cover.
Once installed and working I will post the details, seal costs about $6.50 and you end up with new technology sealing system without paying cadillac drug prices for parts.
Wait until I can get some decent gaskets made at about half the prices being asked right now.
Maybe I am out of order here, but is anybody actually out there with another cadillac flathead
that has or is doing some sort of modifications??

Believe me, we all love everything to do with Cadillacs and LaSalles, and hopefully, there will be someone out there that can assist you in your quest.

But, as others have said, try the Mother Board, as there seem to be a lot more people with a vast knowledge of the Cadillac Flathead engines.

Me personally, I have never owned a Flathead powered vehicle, be it a Cadillac, Dodge, or Ford.   Have owned a few Fords, but the Sidevalves in them was never attempted to be started, as they were coming straight out, for a replacement by "Ollie Overhead".

Some people detest Overheads, and love Sidevalves, but someone somewhere will have what you need, of that I am sure.

Bruce.